One problem with vertical shaft pump systems resides in the fact that the motors for such units are typically located above the pumping impellers thereof such that seals associated with the vertical drive shafts for such impellers are likewise disposed above the normal area of flow and contact with liquid being pumped. Consequently, such seals are subject to more rapid dehydration and failure than would otherwise be the case.
Moreover, presently known vertical shaft systems frequently subject the liquid being pumped to excessive power demands due to friction losses arising from the manner in which the liquid is directed through the various twists and turns of the system's plumbing. Still further, check valves associated with such systems have experienced leakage due to improper and ineffective sealing, and excessive space is frequently needed to adequately contain and house all of the components associated with a particular pumping installation.